package com.itboye.system.crypt;

import java.nio.charset.Charset;
import java.security.SecureRandom;
import java.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

/**
 * Created by hebidu on 16/5/9.
 * @version 2015-8-25
 */
public class DesCrypt {


    /**
     * DES
     * @param key
     * @param data
     * @return
     */
    public static String encode(String content,String key) {
        try{
            SecureRandom random = new SecureRandom();
            DESKeySpec desKey = new DESKeySpec(key.getBytes());
            //创建一个密匙工厂，然后用它把DESKeySpec转换成
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            SecretKey securekey = keyFactory.generateSecret(desKey);
            //Cipher对象实际完成加密操作
            Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
            //用密匙初始化Cipher对象
            cipher.init(Cipher.ENCRYPT_MODE, securekey, random);
            //现在，获取数据并加密
            //正式执行加密操作
            byte[] finalBytes = cipher.doFinal(content.getBytes("UTF-8"));

            byte[] encodeBytes = Base64.getEncoder().encode(finalBytes);

            return new String(encodeBytes, Charset.forName("utf-8"));

        }catch(Throwable e){
            e.printStackTrace();
        }

        return null;

    }

    /**
     * DES
     *
     * @param data base64 加密后的密文
     *
     * @param key
     *
     * @return
     */
    public static String decode(String data, String key) {
        if (data == null)
            return null;
        try {

            byte[] originEncodeBytes = Base64.getDecoder().decode(data);
            // DES算法要求有一个可信任的随机数源
            SecureRandom random = new SecureRandom();
            // 创建一个DESKeySpec对象
            DESKeySpec desKey = new DESKeySpec(key.getBytes());
            // 创建一个密匙工厂
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            // 将DESKeySpec对象转换成SecretKey对象
            SecretKey securekey = keyFactory.generateSecret(desKey);
            // Cipher对象实际完成解密操作
            Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
            // 用密匙初始化Cipher对象
            cipher.init(Cipher.DECRYPT_MODE, securekey, random);
            // 真正开始解密操作
            byte[] origin = cipher.doFinal(originEncodeBytes);
            return new String(origin,"utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

}
